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Mearns Probus Club members hear a fishy tale

Dr. Richard Shelton was the speaker at the latest meeting of the Mearns Probus Club, and his subject was the Atlantic Salmon Trust.

Richard is a director of this body whose main aim is to study the life span of wild salmon from its origin in burns and rivers well away from the sea, and its lifespan in the oceans before finally returning to its birthplace.

With the aid of a fairly short professionally produced DVD. he outlined the reason for the Trust’s formation, then moved on to the main Scottish rivers and then out to sea.

Using specially designed nets with cameras installed, relaying back to the mother ship via a towed inflatable type of small dingy fitted with an aerial, the salmon could be studied while at sea.

The nets used have no end so the fish pass through without killing then along with grilse, parr and any other fish passing through.

Adding a scaled background on a grid fixed opposite the camera, the size of the fish can be recorded as it passes through.

It was thought that most salmon swam at a fairly constant depth in the sea.

However, research has shown that they can dive to greater depths when chasing their source of food.

From the results of all this research, it was found that the Atlantic salmon all make their way towards the Norwegian waters and the Arctic regions for their supply of food and nutrients.

By knowing the approximate depth in the open sea where the salmon live, the fishing boats can vary the depth of their trawl nets to avoid collecting unwanted immature fish unnecessarily.

Aberdeen has a marine laboratory in Torry, where this data is processed and studied. It also ascertains the type of foods the salmon eats as well as the effects of such things as sea lice and of course any predators which reduce their numbers.

The salmon can adapt their bodies to suit fresh water or salt water conditions and can desalinate or change their blood and internal organs to suit as required.

Hopefully, all this will ensure a constant re-generation of salmon in the future.

Our Scottish rivers provide ideal conditions for this life cycle.

Past President Ian Williamson proposed a vote of thanks, following a lengthy question-and-answer session with Richard from club members who enjoyed this fishy tale.

 

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